Heat dissipation device having irregular shape

ABSTRACT

A heat dissipation device includes a first casing and a second casing coupled to the first casing. The second casing includes a body having an inner surface and an outer surface opposite the inner surface, and a first portion and a second portion, each of the first and second portions having a different cross-sectional area. The heat dissipation device further includes a plurality of columns on the inner surface, and a first wick structure disposed on the inner surface and in the first portion and the second portion.

CROSS REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. § 119to U.S. Provisional patent application Nos. 62/783,717 filed Dec. 21,2018, and 62/798,480 filed Jan. 30, 2019, the entire contents of boththese applications are incorporated herein by reference.

BACKGROUND

Vapor chambers have higher efficiency in heat dissipation than heatpipes. A vapor chamber includes a casing and a wick structure. Thecasing defines a chamber for accommodating cooling fluid. The wickstructure is disposed in the chamber. The casing has an evaporationsection for absorbing heat and a condensation section for dissipatingheat. The cooling fluid is evaporated into a gaseous state in theevaporation section, and then turns into a liquid state in thecondensation section and is carried back to the section area by the wickstructure, thereby creating circulating cooling fluid.

Electronic products have become lighter, slimmer, and more compact, and,as a result, vapor chambers are required to have an irregular shape inorder to not interfere or obstruct nearby electrical components. In sucha case, portions of the vapor chamber are required to have reduceddimensions, and the cross-sectional area of the wick structure in theseportions is reduced compared to its cross-sectional area in otherportions of the vapor chamber. In a vertically orientated vapor chamber,when a heat source is in thermal contact with the upper portion of thevapor chamber, cooling fluid in the vapor chamber is required tocirculate against gravity. However, the flow of the cooling fluidstagnates in the reduced dimension portions due to the smallercross-sectional area of the wick structure in these portions. Thus, theflow of the cooling liquid is restricted through the narrow area andcirculation of the cooling fluid in the vapor chamber is inhibited,thereby affecting the operation of the vapor chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1 is an exploded view of a vapor chamber according to embodimentsof the disclosure.

FIG. 2A is a plan view of a second casing of the heat dissipation devicein FIG. 1, according to embodiments of the disclosure.

FIG. 2B illustrates the encircled region 2B of FIG. 2A in greaterdetail.

FIG. 2C illustrates the encircled region 2C of FIG. 2A in greaterdetail.

FIG. 2D is a plan view of the second casing, according to embodiments ofthe disclosure.

FIG. 3 illustrates a plan view of a second casing including two wickstructures, according to embodiments of the disclosure.

FIG. 4 illustrates a plan view of a second casing including three wickstructures, according to embodiments of the disclosure.

FIG. 5A illustrates a plan view of a second casing and a wick structure,according to embodiments of the disclosure.

FIG. 5B illustrates a plan view of the second casing of FIG. 5Aincluding two wick structures, according to embodiments of thedisclosure.

FIG. 6A illustrates a plan view of a second casing and a wick structure,according to embodiments of the disclosure.

FIG. 6B illustrates the second casing of FIG. 6A including the wickstructure of FIG. 6A and an additional wick structure, according toembodiments of the disclosure.

FIG. 7A illustrates a plan view of a second casing including two wickstructures, according to embodiments of the disclosure.

FIG. 7B illustrates a plan view of the second casing of FIG. 7Aincluding a single wick structure, according to embodiments of thedisclosure.

FIG. 8A illustrates a plan view of a second casing including two wickstructures, according to embodiments of the disclosure.

FIG. 8B illustrates a plan view of a second casing including a wickstructure, according to embodiments of the disclosure.

FIG. 8C illustrates a cross-sectional view of the second casing in FIG.8B, according to embodiments of the disclosure.

FIG. 8D illustrates a plan view of the second casing including a singlewick structure 180, according to embodiments of the disclosure.

FIG. 9 illustrates a plan view of a second casing including a wickstructure, according to embodiments of the disclosure.

FIG. 10A is a cross-sectional view of a wick structure includingmultiple wick fibers arranged around a central wick fiber, according toembodiments of the disclosure.

FIGS. 10B-10F illustrate different configurations of the wick structuresof FIG. 10A.

FIG. 10G is a cross-sectional view of a wick structure includingmultiple wick fibers, according to embodiments of the disclosure.

FIGS. 10H, 10J, and 10K illustrate different configurations of the wickstructures of FIG. 10G.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof the disclosure. Specific embodiments or examples of components andarrangements are described below to simplify the present disclosure.These are, of course, merely examples and are not intended to belimiting. For example, dimensions of elements are not limited to thedisclosed range or values, but may depend upon process conditions and/ordesired properties of the device. Moreover, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed interposing the first and second features, suchthat the first and second features may not be in direct contact. Variousfeatures may be arbitrarily drawn in different scales for simplicity andclarity.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The device may be otherwise oriented (rotated 90 degrees orat other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly. In addition, the term“made of” may mean either “comprising” or “consisting of.”

FIG. 1 is an exploded view of a heat dissipation device 100 according toembodiments of the disclosure. FIG. 2A is a plan view of a second casing120 of the heat dissipation device 100 in FIG. 1, according toembodiments of the disclosure. For the purposes of discussion herein,the heat dissipation device 100 is considered to be a vapor chamber.However, embodiments are not limited thereto and embodiments disclosedherein are equally applicable to other types of heat dissipation deviceswithout departing from the scope of the disclosure.

Referring to FIGS. 1 and 2A, the vapor chamber 100 is a generally flat,planar structure including a first casing 110, a second casing 120, afirst wick structure 130, and a second wick structure 140. The vaporchamber 100 is referred to as a thin heat spreader. The vapor chamber100 has a thickness less than approximately 1 millimeter.

The first casing 110 and the second casing 120 may be composed of, forexample, oxygen-free copper, silicon-containing copper alloy,aluminum-containing copper alloy, a combination thereof, and the like.Referring to FIG. 2A, the second casing 120 includes a main body 121 anda plurality of supporting structures 122. The supporting structures 122protrude (or otherwise project) from an inner surface 123 of the mainbody 121 towards the first casing 110 and contact the first casing 110.The supporting structures 122 reduce buckling of the first casing 110and the second casing 120 and thus limit deformation of the vaporchamber 100. In some embodiments, the supporting structures 122 arecolumn or pillar shaped having a diameter of about 0.4 mm to about 0.8mm. However, embodiments are not limited in this regard. Other shapesand sizes are also possible provided the plurality of supportingstructures 122 limit buckling of the first casing 110 and second casing120.

FIG. 2B illustrates the encircled region 2B of FIG. 2A in greaterdetail. In some embodiments, and as illustrated, the supportingstructures 122 are arranged in rows (or columns) with immediatelyadjacent rows offset (or staggered) from each other. For example, asillustrated in FIG. 2B, the supporting structures 122 in row 131 areoffset from the supporting structures 122 in row 133. In someembodiments, the distance D1 between alternate rows of supportingstructures 122 (e.g., rows 131 and 135) is twice the distance betweenadjacent rows of supporting structures 122 (e.g., rows 131 and rows133). In some embodiments, the distance D1 is between 3.5 mm to 4.5 mmand the distance D2 is between 1.5 mm to 2.5 mm. However, embodimentsare not limited in this regard, and the distances D1 and D2 can bevaried as required by application and design provided the plurality ofsupporting structures 122 limit buckling of the first casing 110 andsecond casing 120.

FIG. 2C illustrates the encircled region 2C of FIG. 2A in greaterdetail. As illustrated, the inner surface 123 includes a first fixingstructure 175 along the outer periphery of the second casing 120 and asecond fixing structure 177 surrounding the first fixing structure 175and along the outer periphery of the second casing 120. In someembodiments, the first fixing structure 175 and the second fixingstructure 177 define a channel or groove 173 therebetween. The innersurface of the first casing 110 includes a corresponding protrusion thatis received in the groove 173 for securing the first casing 110 and thesecond casing 120 to each other.

In some embodiments, the thickness of the first casing 110 is smallerthan the thickness of the second casing 120. As an example, thethickness of first casing 110 is about 0.1 mm to about 0.15 mm and thethickness of the second casing 120 is about 0.2 mm to about 0.35 mm. Anoverall thickness of the vapor chamber 100 including the first casing110 and the second casing 120 is about 0.3 mm to 0.5 about mm. However,embodiments are not limited in this regard, and the thickness of thefirst casing 110 may be greater than the thickness of the second casing120.

The inner surface 123 is opposite to the outer surface 125 of the mainbody 121. The outer surface 125 forms part of the outer surface of thevapor chamber 100 and is substantially planar. The first casing 110 isconnected to the main body 121 of the second casing 120 by welding,soldering, brazing, or diffusion bounding. The second casing 120 has afirst or “broad” portion A1 and a second or “narrow” portion A2. Thefirst portion A1 has a width W1 and the second portion A2 has a widthW2. The width W1 is larger than the width W2. The first portion haslength L1 and the second portion has a length L2. The sum of the lengthsL1 and L2 is the length L3 of the longest side of the vapor chamber 100.It will thus be understood that each of the first portion A1 and thesecond portion A2 has a different cross-sectional area. In anembodiment, the width W1 of the first portion A1 is approximately 80millimeters (mm), the width W2 of the second portion A2 is approximately18 mm. The length L1 is about 90 mm to about 100 mm, and the length L3is about 120 mm to about 130 mm. However, embodiments are not limited inthis regard and can be varied depending on the application and designrequirements. In other embodiments, the width W2 of the second portionA2 may be equal to or less than half of the width W1 of the firstportion A1. In still other embodiments, the width W2 of the secondportion A2 may be equal to or less than one-third of the width W1 of thefirst portion A1.

The first wick structure 130 is in a form of a sheet and is disposedbetween the first casing 110 and the second casing 120. The first wickstructure 130 includes, for example, copper mesh. The first wickstructure 130 contacts the first casing 110 and the second wickstructure 140. The first wick structure 130 provides a flow path for thecooling fluid circulating in the vapor chamber 100.

The second wick structure 140 may be or include a bundle of copper wirestwisted to form a single helical structure. The second wick structure140 is located in the gaps between the supporting structures 122 andcontacts the inner surface 123 of the second casing 120, and thereby isin contact with the second casing 120. Although the second wickstructure 140 has been disclosed as a bundle of wires twisted into ahelical structure, embodiments are not limited thereto. In otherembodiments, the second wick structure 140 may be or include a coppersintered powder wick structure including copper wires interlaced ortwisted into a bundle. In some other embodiments, the second wickstructure 140 may be or include a plurality of the bundles of wiresbeing interlaced or twisted. In still other embodiments, the second wickstructure 140 includes a screen mesh wick structure or groove wickstructure.

In an embodiment and as illustrated, the second wick structure 140 is alongitudinally extending structure and is relatively straight (withoutany curves or bends) and is disposed proximate upper ends of the firstportion A1 and second portion A2. One end S of the second wick structure140 is located in the second portion A2 and proximate (but notcontacting) a lateral edge A21 of the second portion A2. The lateraledge A21 is an outer edge of the second portion A2, and thereby of thesecond casing 120. In some embodiments, the end S of the second wickstructure 140 may not contact with the edge A21 of the second portionA2, and may be spaced apart from the edge A21 of the second portion A2.The other longitudinally opposite end E of the second wick structure 140is located in the first portion A1. A heat source H is attached to theouter surface of the first casing 110 and thereby the outer surface ofthe vapor chamber 100 using a thermal paste, or other known techniques.FIG. 2 illustrates a vertical projection (dashed box) of the heat sourceH on the second casing 120. The heat source H is illustrated as squareshaped for the sake of illustration. It will be understood that theshape of the heat source H is not limited to a square shape and the heatsource H can have any desired shaped. The end E of the second wickstructure 140 is spaced (e.g., vertically, in FIG. 2) from the heatsource H by a distance D. The distance D is approximately 18.5 mm, butembodiments are not limited thereto. In some embodiments, the end E ofthe second wick structure 140 may overlap the heat source H or the end Eand boundary (edges) of the heat source H may be coincident. It will beunderstood that the distance D between the end E of the second wickstructure 140 and the heat source H is not limited to any particularvalue and may be adjusted according to the size or shape of the vaporchamber and as per user and design requirements.

The vapor chamber 100 includes a working appendage 1150 that iscooperatively formed by a protrusion 1152 of the second casing 120 and acorresponding protrusion of the first casing 110. The working appendage1150 includes a charging channel 1158 formed by the first casing 110 andthe second casing 120. The charging channel 1158 fluidly communicateswith the interior cavity of the vapor chamber 100 formed by the innersurface 123 of the second casing 120 and the inner surface of the firstcasing 110. The working appendage 1150 is used to fill the interiorcavity of the vapor chamber 100 with working fluid and vacuuming out theair from the interior cavity. In some embodiments, the working appendage1150 is centrally located along the width W1. However, in otherembodiments, the working appendage 1150 is located offset from thecentral location or located on other sides or surfaces of the vaporchamber 100.

FIG. 2D is a plan view of the second casing 120, according toembodiments of the disclosure. In contrast to FIG. 2A, as illustrated,the second wick structure 140 is located proximate a lower end of thesecond portion A2. The distance D between the end E of the second wickstructure 140 and the heat source H is thus reduced. The second wickstructure 140 is spaced from the lateral edge A21 of the second portionA2.

In some embodiments, the vapor chamber 100 may include more than onesecond wick structure 140. FIG. 3 illustrates a plan view of a secondcasing 120 a including two wick structures 141 a and 142 a, according toembodiments of the disclosure. The second casing 120 a may be usedinstead of the second casing 120 in FIGS. 1 and 2 in the vapor chamber100. The second casing 120 a may be similar in some respects to thesecond casing 120 in FIG. 2, and therefore may be best understood withreference thereto where like numerals designate like components notdescribed again in detail.

As illustrated, each of the wick structures 141 a and 142 a arelongitudinally extending structures and are straight structures (withoutbends or curves) and are disposed on the second casing 120 a. The wickstructures 141 a and 142 a are located in the gaps between thesupporting structures 122 and each contacts the inner surface 123 of thesecond casing 120 a. In an embodiment, the wick structures 141 a and 142a have different lengths. For example, and as illustrated, the wickstructure 141 a is longer than the wick structure 142 a. The wickstructures 141 a and 142 a contact each other along the longitudinaledges thereof and are arranged side by side. One end Sa1 of the wickstructure 141 a is located in the second portion A2 and is in contactwith the edge A21 of the second portion A2. The longitudinally oppositeend Ea1 of the wick structure 141 a is located in the first portion A1and spaced (e.g., vertically, in FIG. 3) from the heat source H. One endSa2 of the wick structure 142 a is located in the second portion A2, andthe longitudinally opposite end Ea2 of the wick structure 142 a islocated in the first portion A1 and spaced (e.g., vertically, in FIG. 3)from the heat source H. As illustrated, the ends Ea1 and Ea2 arecoincident with each other (e.g., located at a same distance from theedge A21). However, in other embodiments, the ends Ea1 and Ea2 arenon-coincident (e.g., located at different distances from edge A21) inthe first portion A1.

Compared to the embodiment in FIG. 2, the second casing 120 a in FIG. 3includes the additional wick structure 142 a extending from the secondportion A2 toward the heat source H. The wick structure 142 a improvescirculation of cooling fluid in the vapor chamber 100, for example,against gravity. Thus, the efficiency of the vapor chamber 100 indissipating heat is improved.

FIG. 4 illustrates a plan view of a second casing 120 b including threewick structures 141 a, 142 a, and 143 a, according to embodiments of thedisclosure. The second casing 120 b may be used instead of the secondcasing 120 in FIGS. 1 and 2 in the vapor chamber 100. The second casing120 b may be similar in some respects to the second casings 120 and 120a in FIGS. 2 and 3, and therefore may be best understood with referencethereto where like numerals designate like components not describedagain in detail.

Referring to FIG. 4, each of the wick structures 141 a, 142 a, and 143 aare longitudinally extending structures and are straight structures(without bends or curves), and are disposed on the second casing 120 b.The wick structures 141 a, 142 a, and 143 a are located in the gapsbetween the supporting structures 122 and each contacts the innersurface 123 of the second casing 120 b. In an embodiment, the wickstructures 141 a, 142 a, and 143 a have different lengths. For example,and as illustrated, the wick structure 141 a is longer than the wickstructures 142 a and 143 a. The wick structures 141 a and 142 a contacteach other along the longitudinal edges thereof and arranged side byside. The wick structure 143 a is spaced (e.g., vertically, in FIG. 4)from the wick structures 141 a and 142 a. One end Sa1 of the wickstructure 141 a is located in the second portion A2 and contacts theedge A21 of the second portion A2. The longitudinally opposite end Ea1of the wick structure 141 a is located in the first portion A1 andspaced from the heat source H (illustrated in phantom). One end Sa2 ofthe wick structure 142 a is located in the second portion A2, and thelongitudinally opposite end Ea2 of the wick structure 142 a is locatedin the first portion A1 and spaced from the heat source H. Asillustrated, the ends Ea1 and Ea2 are coincident with each other (e.g.,located at a same distance from the edge A21). However, in otherembodiments, the ends Ea1 and Ea2 are non-coincident. One end Ea3 of thewick structure 143 a is collinear (e.g., aligned) with the heat source Hon the outer surface of first casing 110, and the other end Sa3 of thewick structure 143 a is located in the first portion A1 and contacts avertical edge A11 of the first portion A1. As illustrated, the wickstructure 143 a is entirely within the first portion A1. The horizontaldistance between the end Ea3 of the wick structure 143 a and the heatsource H is less than the vertical distance between the end Ea2 of thewick structure 142 a and the heat source H. Although, the wickstructures 141 a, 142 a, and 143 a are indicated as having differentlengths, embodiments are not limited thereto. In some embodiments, thewick structures 142 a and 143 a may have the same lengths. In otherembodiments, the end Sa1 of the wick structure 141 a and end Sa2 of thewick structure 142 a may be located at a same distance from the edgeA21.

Compared to embodiment of FIG. 3, the second casing 120 b in of FIG. 4includes an additional wick structure 143 a extending from the edge ofthe first portion A1 toward the heat source H. The wick structure 143 afurther improves circulation of cooling fluid in the vapor chamber 100,for example, against gravity. Thus, the efficiency of the vapor chamber100 in dissipating heat is further improved.

FIG. 5A illustrates a plan view of a second casing 120 c and a wickstructure 140 c, according to embodiments of the disclosure. The secondcasing 120 c may be used instead of the second casing 120 in FIGS. 1 and2 in the vapor chamber 100. The second casing 120 c may be similar insome respects to the second casing 120 in FIG. 2, and therefore may bebest understood with reference thereto where like numerals designatelike components not described again in detail.

As illustrated, the wick structure 140 c is disposed in the secondcasing 120 c and has at least one bend. The wick structure 140 c islocated in the gaps between the supporting structures 122 and contactsthe inner surface 123 of the second casing 120. An end Sc of the wickstructure 140 c is located in the second portion A2 and contacts theedge A21 of the second portion A2 and the opposite end Ec of the wickstructure 140 c is located in the first portion A1 and overlaps at leastpart of the heat source H (illustrated in phantom) attached to the outersurface of the first casing 110. In an example, and as illustrated, thewick structure 140 c at least partially overlaps one side or end of theheat source H that is closer to the wick structure 140 c. For the sakeof explanation, it is assumed that the heat source H has a generallyrectangular shape including a first side L1 and a second side L2opposite the first side L1, and a third side L3 and a fourth side L4opposite the third side L3. The first side L1 is closer to the edge A21.The fourth side L4 is closer to the wick structure 140 c. The wickstructure 140 c overlaps the fourth side L4 of the heat source H.

As illustrated, the wick structure 140 c includes two sections 1401 and1402, having lengths Y1 and Y2, respectively. The sections 1401 and 1402are connected to each other at an angle (greater than 0° and less than180°). The overall length of the wick structure 140 c is the sum of thelengths Y1 and Y2. In an example, the overall length is approximately118 mm, but the disclosure is not limited thereto. In other embodiments,the overall length of the wick structure 140 c increased or decreased aslong as the wick structure 140 c is accommodated within the vaporchamber 100. In an embodiment, an extent of the wick structure 140 c maybe equal to the minimum distance X between the end Sc of the wickstructure 140 c and the heat source H. More specifically, the minimumdistance X is measured from the end Sc to a point on the heat source Hnearest to the end Sc as projected vertically on the inner surface 123.For instance, the distance X is approximately 105 mm. The heatdissipation efficiency of the vapor chamber including the wick structure140 c is relatively higher when the overall length of the wick structure140 c is equal to or less than about 126 mm.

The wick structure 140 c decreases a distance the cooling fluid has tocirculate in the vapor chamber 100. The length of the wick structure 140c is not limited to any particular length and may be adjusted accordingto user and design requirements.

FIG. 5B illustrates a plan view of the second casing 120 c including thewick structure 140 c and a wick structure 150 c, according toembodiments of the disclosure. The wick structure 150 c is shaped andsized (or otherwise configured) similar to the wick structure 140 c. Thewick structure 150 c contacts the wick structure 140 c at a bottom sidethereof. As illustrated, the wick structure 150 c is located in the gapsbetween the supporting structures 122 and contacts the inner surface 123of the second casing 120 c. An end 155 of the wick structure 150 c islocated in the second portion A2 and contacts the edge A21 of the secondportion A2 and the opposite end 157 of the wick structure 150 c islocated in the first portion A1 and overlaps at least part of the heatsource H (illustrated in phantom) attached to the outer surface of thefirst casing 110. As depicted, the ends 155 and 157 of the wickstructure 150 c are aligned with the ends Sc and Ec of the wickstructure 140 c.

In some embodiments, the wick structure 150 c overlaps a same side ofthe heat source H as overlapped by the wick structure 140 c. In otherembodiments, the wick structure 150 c overlaps a different side of theheat source H.

The wick structure 150 c includes sections 1501 and 1502 having lengthsY1 and Y2, respectively, are connected to each other at a same angle(greater than 0° and less than 180°) as the sections 1401 and 1402 ofthe wick structure 140 c. However, in other embodiments, the lengths ofthe sections 1501 and 1502 are different from the lengths of thesections 1401 and 1402. In some embodiments, the length of the section1501 is smaller than the length of the section 1401. In some otherembodiments, the length of the section 1502 is longer than the length ofthe section 1402.

The location of the wick structure is not restricted to any particularlocation in the vapor chamber. FIG. 6A illustrates a plan view of asecond casing 120 d and a wick structure 140 d, according toembodiments. The second casing 120 d may be used instead of the secondcasing 120 of FIGS. 1 and 2 in the vapor chamber 100. The second casing120 d may be similar in some respects to the second casing 120 c in FIG.5A, and therefore may be best understood with reference thereto wherelike numerals designate like components not described again in detail.

Referring to FIG. 6A, the wick structure 140 d has at least one bend andis disposed on the second casing 120 d. The wick structure 140 d islocated in the gaps between the supporting structures 122 and contactsthe inner surface 123 of the second casing 120 d. One end Sd of the wickstructure 140 d is located in the second portion A2, and the otheropposite end Ed of the wick structure 140 d is located in the firstportion A1 and overlaps the heat source H attached to the outer surfaceof the first casing 110. Assuming, for the sake of explanation, that theheat source H is the same as the heat source H in FIG. 5A, the wickstructure 140 d overlaps the first side L1. As illustrated, the sectionhaving length Y1 of the wick structure 140 d contacts a lower horizontaledge A22 of the second portion A2.

The wick structure 140 d has a relatively shorter length that the wickstructure 140 c of FIG. 5A. The overall length of the wick structure 140d is approximately 108 mm, but the disclosure is not limited thereto. Inother embodiments, the overall length of the wick structure 140 dincreased or decreased as long as the wick structure 140 c isaccommodated within the vapor chamber 100. An extent of the wickstructure 140 d may be equal to the minimum distance X between the endSd of the wick structure 140 d and the heat source H. More specifically,the minimum distance X is measured from the end Sd to a point on theheat source H nearest to the end Sd projected vertically on the innersurface 123. For example, the distance X is approximately 100 mm. Theheat dissipation efficiency of the vapor chamber including the wickstructure 140 c is relatively higher when the overall length of the wickstructure 140 d is equal to or less than about 120 mm.

FIG. 6B illustrates the second casing 120 d including the wick structure140 d and a wick structure 150 d, according to embodiments of thedisclosure. The wick structure 150 d is shaped and sized (or otherwiseconfigured) similar to the wick structure 140 d. The wick structure 150d contacts the wick structure 140 d at the top side thereof. The wickstructure 150 d is located in the gaps between the supporting structures122 and contacts the inner surface 123 of the second casing 120 d.

An end 165 of the wick structure 150 d is located in the second portionA2 and is spaced from the edge A21 of the second portion A2 and theopposite end 167 of the wick structure 150 d is located in the firstportion A1 and overlaps at least part of the heat source H (illustratedin phantom) attached to the outer surface of the first casing 110. Asdepicted, the ends 165 and 167 of the wick structure 150 d are alignedwith the ends Sd and Ed of the wick structure 140 d.

In some embodiments, the wick structure 150 d overlaps a same side ofthe heat source H as overlapped by the wick structure 140 d. In otherembodiments, the wick structure 150 d overlaps a different side of theheat source H.

The wick structure 150 d sections 1501 and 1502 having lengths Y1 andY2, respectively, are connected to each other at a same angle (greaterthan 0° and less than 180°) as the sections 1401 and 1402 of the wickstructure 140 d. However, in other embodiments, the lengths of thesections 1501 and 1502 are different from the lengths of the sections1401 and 1402. In some embodiments, the length of the section 1501 issmaller than the length of the section 1401. In some other embodiments,the length of the section 1502 is longer than the length of the section1402.

Referring to FIGS. 5A and 6A, the wick structure 140 d in FIG. 6A isshorter than the wick structure 140 c in FIG. 5A, and this reduces thepath for the cooling liquid to circulate in the vapor chamber 100. Thelength of the wick structure 140 d is not limited to any particularlength and may be adjusted according to user and design requirements.

According to embodiments, the shapes of the first casing and the secondcasing are not limited to any particular shape. FIG. 7A illustrates aplan view of a second casing 120 e including two wick structures 141 eand 142 e, according to embodiments of the disclosure. The second casing120 e may be used in a vapor chamber that includes a first casing and asheet-like wick structure similar to the first casing 110 and the firstwick structure 130 in FIG. 1, respectively, but each having a shapecorresponding to the shape of the second casing 120 e.

As illustrated in FIG. 7A, the second casing 120 e is generally H-shapedand has a first portion A1, a second portion A2, and a third portion A3.The third portion A3 is located between the first section A1 and secondsection A2. The first portion A1 has a width W1, the second portion A2has a width W2, and the third portion A3 has a width W3. The width W1 isequal to the width W2, and the width W3 is smaller than the width W1.However, in other embodiments the widths W1 and W2 may be different, buteach greater than the width W3. The wick structures 141 e and 142 e aredisposed on the second casing 120 e. The wick structures 141 e and 142 eeach have a generally L-shape and are located in the gaps between thesupporting structures 122 and each contacts the inner surface 123 of thesecond casing 120 e.

The wick structure 141 e includes a first section 151 that is disposedin the first portion A1, second portion A2, and third portion A3. Thewick structure 141 e includes a second section 152 disposed in thesecond portion A2 and at an angle relative to the first section 151. Thefirst section 151 is connected to the second section 152 in the secondportion A2. In an example, the first section 151 is perpendicular to thesecond section 152. However, embodiments are not limited thereto, andthe first section 151 is connected to the second section 152 at anglesgreater than or less than 90°.

The wick structure 142 e includes a first section 153 that is disposedin the first portion A1, second portion A2, and third portion A3. Thewick structure 142 e includes a second section 154 disposed in thesecond portion A2 and at an angle relative to the first section 153. Thefirst section 153 is connected to the second section 154 in the secondportion A2. In an example, the first section 153 is perpendicular to thesecond section 154. However, embodiments are not limited thereto, andthe first section 153 is connected to the second section 154 at anglesgreater than or less than 90°. The first section 151 of the wickstructure 141 e and the first section 153 of the wick structure 141 econtact each other.

The first section 151 includes an end Ee1 of the wick structure 141 e inthe first portion A1. The end Ee1 overlaps the heat source H attached tothe outer surface of the first casing 110. The first section 153includes an end Ee2 of the wick structure 142 e in the first portion A1.The end Ee1 overlaps the heat source H attached to the outer surface ofthe first casing 110.

The second section 152 includes an end Se1 of the wick structure 141 ein the second portion A2. The second section 154 includes an end Se2 ofthe wick structure 142 e in the second portion A2.

As illustrated, the end Se1 of the wick structure 141 e is locatedproximate (non-contacting) an upper edge A22 of the second portion A2and the end Se2 of the wick structure 142 e is located proximate a loweredge A23 of the second portion A2 opposite the upper edge A22. Thesecond sections 152 and 154 are disposed proximate the edge A21 of thesecond portion A2. The edge A21 connects the upper edge A22 and loweredge A23. In other embodiments, the end Se1 may contact the upper edgeA22, the end Se2 may contact the lower edge A23, and the second sections152 and 154 contact the edge A21.

Instead of two wick structures 141 e and 142 e, some embodiments includea single wick structure. FIG. 7B illustrates a plan view of the secondcasing 120 e including a single wick structure 170, according toembodiments of the disclosure. The wick structure 170 includes a firstsection 171 disposed in the first portion A1, second portion A2, andthird portion A3. The wick structure 170 includes a second section 172disposed in the second portion A2 and at an angle relative to the firstsection 171. The first section 171 is connected to the second section172 in the second portion A2. In an example, the first section 171 isperpendicular to the second section 172. However, embodiments are notlimited thereto, and the first section 171 is connected to the secondsection 172 at angles greater than 0° or less than 90°.

The first section 171 includes an end Ee1 of the wick structure 170 inthe first portion A1. The end Ee1 overlaps the heat source H attached tothe outer surface of the first casing 110. The second section 172includes an end Se1 of the wick structure 170 in the second portion A2.The second section 172 includes an end Set opposite end Se1 located inthe second portion A2. The second section 172 is disposed proximate theedge A21 of the second portion A2.

FIG. 8A illustrates a plan view of a second casing 120 f including twowick structures 141 f and 142 f, according to embodiments of thedisclosure. The second casing 120 f may be used in a vapor chamber thatincludes a first casing and a sheet-like wick structure similar to thefirst casing 110 and the first wick structure 130 in FIG. 1,respectively, but each having a shape corresponding to the shape of thesecond casing 120 f.

The second casing 120 f includes a first portion A1 disposed between asecond portion A2 and a third portion A3. The first portion A1 has awidth W1, and the second portion A2 and the third portion A3 each have awidth W2. The width W1 is larger than the width W2. In otherembodiments, the second portion A2 and the third portion A3 may havedifferent widths, but smaller than the width W1. The wick structures 141f and 142 f are disposed on the second casing 120 f. The wick structures141 f and 142 f each have a generally L-shape and are located in thegaps between the supporting structures 122 and each contacts the innersurface 123 of the second casing 120 f.

The wick structure 141 f includes a first section 161 that is disposedin the first portion A1. The wick structure 141 f includes a secondsection 162 disposed in the first portion A1 and the second portion A2and at an angle relative to the first section 161. The first section 161is connected to the second section 162 in the first portion A1. In anexample, the first section 161 is perpendicular to the second section162. However, embodiments are not limited thereto, and the first section161 is connected to the second section 162 at angles greater than orless than 90°.

The wick structure 142 f includes a first section 163 that is disposedin the first portion A1. The wick structure 142 f includes a secondsection 164 disposed in the third portion A3 and at an angle relative tothe first section 163. The first section 163 is connected to the secondsection 164 in the first portion A1. In an example, the first section163 is perpendicular to the second section 164. However, embodiments arenot limited thereto, and the first section 163 is connected to thesecond section 164 at angles greater than or less than 90°. The firstsection 161 of the wick structure 141 f and the first section 163 of thewick structure 142 f contact each other.

The first section 161 includes an end Ef1 of the wick structure 141 flocated in the first portion A1. The end Ef1 overlaps the heat source Hattached to the outer surface of the first casing 110. The first section163 includes an end Ef2 of the wick structure 142 f in the first portionA1. The end Ef2 overlaps the heat source H attached to the outer surfaceof the first casing 110.

The second section 162 includes an end Sf1 of the wick structure 141 fin the second portion A2. The second section 164 includes an end Sf2 ofthe wick structure 142 f in the third portion A3.

As illustrated, the end Sf1 of the wick structure 141 f is locatedproximate an edge A32 of the second portion A2 and the end Sf2 of thewick structure 142 f is located proximate an edge A33 of the thirdportion A3 opposite the edge A32. The second sections 162 and 164 aredisposed proximate (but not contacting) an edge A31 of the second casing120 f that forms (or otherwise defines) the first portion A1, the secondportion A2, and the third portion A3 of the second casing 120 f. Theedge A31 connects the edge A32 and edge A33. In other embodiments, theend Sf1 may contact the edge A32, the end Sf2 may contact the edge A33,and the second sections 162 and 164 contact the edge A31.

When the vapor chamber is used in a vertical manner (e.g., in a positionwherein the heat source H is located at a level higher than the secondportion A2 and third portion A3), the cooling fluid in the vapor chamberevaporates and turns to vapor while absorbing the heat generated by theheat source H. The cooling fluid (in vapor state) flows toward thesecond portion A2 and the third portion A3 and turns back to liquidstate, and the cooling fluid can flow to the first portion A1 via thewick structures 141 f and 142 f. This configuration decreases atemperature difference between the first portion A1 and the secondportion A2 and the third portion A3 by around 4 to 15 degrees Celsius.The cooling fluid continuously circulates between the first portion A1and the second portion A2 and the third portion A3, thereby dissipatingthe heat generated by the heat source H.

FIG. 8B illustrates a plan view of a second casing 120 g including awick structure 142 f, according to embodiments. FIG. 8C illustrates across-sectional view of the second casing 120 g taken along line 8B-8Bin FIG. 8B. The second casing 120 g may be similar in some respects tothe second casing 120 f in FIG. 8A, and therefore may be best understoodwith reference thereto where like numerals designate like components notdescribed again in detail.

As illustrated in FIG. 8B, the second casing 120 g includes a singlewick structure 142 f. The wick structure 141 f is absent. The wickstructure 142 f is spaced from the edge A31. In some embodiments, thesecond section 164 is disposed mid-way in the third portion A3. In someembodiments, and as illustrated, the first section 163 of the wickstructure 142 f is centrally located in the first portion A1. However,embodiments are not limited in this regard and in some otherembodiments, the first section 163 is located offset from the center ofthe first portion A1.

In some embodiments, the second casing 120 g includes the wick structure141 f (FIG. 8A) and the wick structure 142 f is absent. The wickstructure 141 f is spaced from the edge A31. In some embodiments, thesecond section 162 of the wick structure 141 f is disposed mid-way withrespect to the width direction W2 in the second portion A2. In someembodiments, the first section 161 (FIG. 8A) of the wick structure 141 fis centrally located in the first portion A1. However, in some otherembodiments, the first section 161 is located offset from the center ofthe first portion A1.

Instead of two wick structures 141 f and 142 f, some embodiments includea single wick structure. FIG. 8D illustrates a plan view of the secondcasing 120 f including a single wick structure 180, according toembodiments of the disclosure. The wick structure 180 includes a firstsection 181 disposed in the first portion A1. The wick structure 180includes a second section 182 disposed in the first portion A1, secondportion A2, and third portion A3 and at an angle relative to the firstsection 181. The first section 181 is connected to the second section182 in the first portion A1. In an example, the first section 181 isperpendicular to the second section 182. However, embodiments are notlimited thereto, and the first section 181 is connected to the secondsection 182 at angles greater than 0° or less than 90°.

The first section 181 includes an end Ef1 of the wick structure 180 inthe first portion A1. The end Ef1 overlaps the heat source H attached tothe outer surface of the first casing 110. The second section 182includes an end Sf1 of the wick structure 180 in the second portion A2and an end Sf2 opposite end Sf1 located in the third portion A3. Thesecond section 182 is disposed proximate (but not contacting) the edgeA31 that forms (or otherwise defines) the first portion A1, the secondportion A2, and the third portion A3 of the second casing 120 f.Although not illustrated, a working appendage similar to the workingappendage 1150 in FIG. 2A is included in the second casing 120 f inFIGS. 8A, 8B, and 8D. The working appendage is located at any desirablelocation along the sides of the second casing 120 f.

FIG. 9 illustrates a plan view of a second casing 120 h including a wickstructure 141 h, according to embodiments of the disclosure. The secondcasing 120 h may be used in a vapor chamber that includes a first casingand a sheet-like wick structure similar to the first casing 110 and thefirst wick structure 130 in FIG. 1, respectively, but each having ashape corresponding to the shape of the second casing 120 h.

As illustrated in FIG. 9, the second casing 120 h is generally U-shapedand has a horizontally orientated first portion A1, and a second portionA2 and a third portion A3, each vertically oriented. The first portionA1 is located between the second and third sections A2 and A3. The firstportion A1 has a width W1, the second portion A2 has a width W2, and thethird portion A3 has a width W3. The width W2 is equal to the width W3,and the width W1 is less than the widths W2 and W3. However, in otherembodiments the widths W2 and W3 may be different, but each greater thanthe width W1. The wick structure 141 h is disposed in the second casing120 h and in the gaps between the supporting structures 122. The wickstructure 141 h contacts the inner surface 123 of the second casing 120h.

The wick structure 141 h includes a first section 191 horizontallyoriented and disposed in the first portion A1, second portion A2, andthird portion A3. The wick structure 141 h includes two verticallyoriented sections, a second section 192 disposed in the second portionA3 and a third section 193 disposed in the third portion A3. The secondsection 192 and the third section 193 are transverse to the firstsection 191. In an embodiment, the second section 192 and the thirdsection 193 are perpendicular to the first section 191. However,embodiments are not limited in this regard and the second section 192and the third section 193 can be disposed at angles greater than 0° andless than 180° with reference to the first section 191. Each of thefirst section 191, second section 192, and third section 193 arestraight, longitudinal structures without any bends. The second section192 and the third section 193 are angled relative to the first section191. The second section 192 and the third section 193 are connected tothe first section 191 in the second portion A2 and the third portion A3,respectively. In an embodiment, and as illustrated, the second section192 and the third section 193 are perpendicular to the first section191. However, embodiments are not limited in this regard, and the secondsection 192 and the third section 193 are connected to the first section191 at angles greater than 0° or less than 90°.

The first section 191 includes an end Sg2in the second portion A2, andproximate an outer vertical edge A22 of the second portion A2. The firstsection 191 includes an end Sg3 in the third portion A3 longitudinallyopposite the end Sg2, and proximate an outer vertical edge A23 of thethird portion A3. The first section 191 is located proximate a bottomedge A21 of the first portion A1, second portion A2, and third portionA3.

The second section 192 includes an end Eg2 in the second portion A2. Theend Eg2 is longitudinally opposite the end of the second section 192connected to the first section 191. Similarly, the third section 193includes an end Eg3 in the third portion A3. The end Eg3 islongitudinally opposite the end of the third section 193 connected tothe first section 191.

As illustrated, the end Eg2 overlaps the heat source H attached to theouter surface of the first casing 110 and over the second portion A2.However, in other embodiments, the end Eg3 overlaps the heat source Hattached to the outer surface of the first casing 110 and over the thirdportion A3. A working appendage 1150 is located in the third portion A3.However in other embodiments, the working appendage 1150 is located inthe first portion A1 or the second portion A2 along any desired edge.

FIG. 10A is a cross-sectional view of a wick structure includingmultiple wick fibers 1010 arranged around a central wick fiber 1020. Inan embodiment, the wick fibers 1010 and 1020 include copper. However,the wick fibers 1010 and/or 1020 can include other materials thatfacilitate the flow of condensed fluid by capillary force through thewick structure formed using the wick fibers 1010 and 1020.

FIGS. 10B-10F illustrate wick structures 140 g, 140 h, 140 i, 140 j, and140 k including different arrangements of the wick fibers 1010 aroundthe central wick fiber 1020. In FIG. 10B, the wick structure 140 gincludes the wick fibers 1010 twisted together in the shape of a helixto form a (e.g., a structure similar to a braided rope). In FIG. 10C,the wick structure 140 h includes the wick fibers 1010 individuallytwisted and then twisted together in the shape of a helix to form abundle. In FIG. 10D, the wick structure 140 i includes the wick fibers1010 longitudinally extending and arranged side by side.

In FIGS. 10E and 10F, the wick structures 140 j and 140 k are formed bytwisting the wick fibers 1010 in the shape of a helix to form a bundle.Due to the difference in the angle of twist of the wires in the wickstructures 140 j and 140 k, the two wick structures 140 j and 140 k havea different tensile force.

In some other embodiments, the central wick fiber 1020 is absent in thewick structures 140 g, 140 h, 140 i, 140 j, and 140 k.

FIG. 10G is a cross-sectional view of a wick structure including aplurality of wick fibers 1030 arranged in a circular manner. In anembodiment, the wick fibers 1030 include copper. However, the wickfibers 1030 can include other materials that facilitate the flow ofcondensed fluid by capillary force through the wick structure formedusing the wick fibers 1030.

FIG. 10H illustrates a wick structure 140 m in which the plurality ofwick fibers 1030 are loosely twisted together. FIG. 10J illustrates awick structure 140 n in which the plurality of wick fibers 1030 arelongitudinally arranged. FIG. 10K illustrates a wick structure 140 p inwhich the plurality of wick fibers 1030 are twisted together or in pairsto form a braided structure. In some other embodiments, the wick fibers1010, 1020, and/or 1030 are flattened.

The shape of the wick structures (e.g., 140, 141 a, 142 a, 143 a, 140 c,150 c, 140 d, 150 d, 141 e, 142 e, 141 f, 141 h, 142 f, 170, and 180) isnot limited to any particular shape. In some embodiments, the wickstructures may be in a zig-zag shape or any other desired shape.

The foregoing outlines features of several embodiments or examples sothat those skilled in the art may better understand the aspects of thepresent disclosure. Those skilled in the art should appreciate that theymay readily use the present disclosure as a basis for designing ormodifying other processes and structures for carrying out the samepurposes and/or achieving the same advantages of the embodiments orexamples introduced herein. Those skilled in the art should also realizethat such equivalent constructions do not depart from the spirit andscope of the present disclosure, and that they may make various changes,substitutions, and alterations herein without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A heat dissipation device, comprising: a firstcasing; a second casing coupled to the first casing, the second casingincluding: a body having, an inner surface and an outer surface oppositethe inner surface, a first portion and a second portion, each of thefirst and second portions having a different cross-sectional area, and aplurality of columns on the inner surface; and a first wick structuredisposed on the inner surface and in the first portion and the secondportion.
 2. The heat dissipation device of claim 1, wherein the firstportion and the second portion have different widths.
 3. The heatdissipation device of claim 1, further comprising: a second wickstructure disposed on the inner surface and in the first portion and thesecond portion.
 4. The heat dissipation device of claim 3, wherein thefirst and second wick structures have different lengths.
 5. The heatdissipation device of claim 3, wherein the first and second wickstructures contact each other along longitudinal edges thereof.
 6. Theheat dissipation device of claim 3, wherein the first and second wickstructures are spaced from a heat source located on the outer surface ofthe second casing.
 7. The heat dissipation device of claim 3, furthercomprising: a third wick structure disposed on the inner surface and inthe first portion.
 8. The heat dissipation device of claim 7, whereinthe first, second, and third wick structures have different lengths. 9.The heat dissipation device of claim 7, wherein the first and secondwick structures are spaced from a heat source outer surface of the firstcasing, and the third wick structure is aligned with the heat source.10. The heat dissipation device of claim 1, wherein the first wickstructure has at least one bend.
 11. The heat dissipation device ofclaim 10, wherein at least a portion of the first wick structure atleast partially overlaps a heat source outer surface of the firstcasing.
 12. A heat dissipation device, comprising: a first casing; asecond casing coupled to the first casing, the second casing including:a body having an inner surface and an outer surface opposite the innersurface, and a first portion, a second portion, and a third portion,each of the first and second portions having a same cross-sectionalarea, the third portion having a cross-sectional area different from thecross-sectional areas of the first and second portions and the thirdportion located between the first and second portions; and a pluralityof columns on the inner surface; and a first wick structure disposed onthe inner surface and in at least two of the first, second, and thirdportions.
 13. The heat dissipation device of claim 12, wherein thecross-sectional area of the third portion is larger than cross-sectionalareas of the first and second portions.
 14. The heat dissipation deviceof claim 12, wherein the cross-sectional area of the third portion issmaller than cross-sectional areas of the first and second portions. 15.The heat dissipation device of claim 12, further comprising: a secondwick structure disposed on the inner surface and in at least two of thefirst, second, and third portions.
 16. The heat dissipation device ofclaim 15, wherein the first and second wick structures contact an edgeof the heat dissipation device that forms at least two of the first,second, and third portions.
 17. The heat dissipation device of claim 15,wherein the first and second wick structures are spaced from an edge ofthe heat dissipation device that forms at least two of the first,second, and third portions.
 18. The heat dissipation device of claim 15,wherein the first and second wick structures are disposed in the first,second, and third portions.
 19. The heat dissipation device of claim 15,wherein the first wick structure is disposed in the first portion andthe third portion, and the second wick structure is disposed in thesecond portion and the third portion.
 20. The heat dissipation device ofclaim 15, wherein each of the first and second wick structures have atleast one bend.
 21. The heat dissipation device of claim 12, wherein theheat dissipation device includes only the first wick structure and thefirst wick structure is spaced from an edge of the heat dissipationdevice that forms at least two of the first, second, and third portions.22. The heat dissipation device of claim 12, wherein each of the firstwick structure and the second wick structure at least partially overlapsa heat source outer surface of the first casing.